Pneumatic dispatch tube apparatus



March 20, 1934. J. T. NEEDHAM PNEUMATIC DISPATCH TUBE APPARATUS OriginalFiled Dec.

INVENTOR JOHN T. NEEDHAM l am ATTORN EYS March 20, 1934. J, T NEEDHAM1,951,367

PNEUMATIC DISPATCH TUBE APPARATUS Original Filed Dec. 6, 1930 3Sheets-Sheet 2 W. 5 23u71 Z3/72 76 @i 4p .3.5i 1E, `9A/Z5 y`7Z INVENTORJOHN T. NEEDHAM ATTORNEYS 6, 195o 3 Sheets-sheet s J. T. NEEDHAMPNEUMATIC DISPATCH TUBE APPARATUS Original Filed Deo.

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March 20, 1934.

Patented Mar. 20, 1934 UNITED STATES PATENT OFFICE to General ConveyorsLimited, Montreal,

Quebec, Canada, a corporation of Canada Application December 6, 1930,Serial No. 500,443 Renewed March 30, 1932 28 Claims.

Important objecs of the present invention are, to provide a sendingterminal device of generally improved design for a pneumatic dispatchtube apparatus; to provide an improved sending terminal device designedto expedite the passage of inserted carriers from a carrier inlet to adispatch tube; to provide for positive and quick pneumatic propulsion ofinserted carriers from the inlet to the dispatch tube; to providesatisfactory valve means for controlling said carrier propulsion; toprovide a multiple sending terminal device of improved design; toprovide a multiple sending terminal device formed of a plurality ofterminal units designed for convenient assembly 1,5 in varying numbers;to provide a multiple sending terminal device wherein each terminal hasmeans for controlling the carrier propelling air, and means are providedfor automatically restoring a previously operated air control means ofone 2G terminal to normal position when the control means of anotherterminal is operated; and to provide a sending terminal device withother irnproved features of design which will be described hereinafter.

In the drawings, Fig. 1 is a top plan view of the multiple terminaldevice;

Fig. 2 a horizontal section taken through one end of the device, on theline 2--2 of Fig. 4;

Fig. 3 a horizontal section taken through the opposite end of thedevice, on the line 3.-3 of Fig. 4;

Fig. 4 a vertical section taken on the line 4-4 of Fig. 1;

Fig. 5 a vertical section taken on the line 5-5 of Fig. 4; and

Fig. 6 a vertical section taken on the line 6-.6 of Fig. 5, showing oneof the control levers depressed.

In the present instance the device comprises three sending terminalunits detachably joined together and forming a compact assembly. Ihenumber of units may be varied according to the needs of the service.Each unit includes two sending terminals together with improved air fcontrol means for causing positive Jtransmission of carriers from saidterminals to and along the dispatch tubes connected to the device. Asingle manifold supplies compressed air to all of the units for thepropulsion of the carriers, and the air control means for the variousterminals are all operaively connected together by means which cause thereturn of a previously operated control means to normal position whenanother one is operated.

Each terminal unit includes a narrow, box-like casing 1, preferablyformed by a single casting. Said casing has vertical end walls 2 and 3,a bottom wall 4 and a central partition web 5 dividing the interior ofthe casing into halves. Each half is subdivided by vertical webs 6 and 760 and by horizontal webs or walls 8, 9, 10 and 11. Thereby at each sideof the partition web 5 a number of spaces and chambers are dened, in-vcluding a space 12 containing part of the air control means, an airpassage 13 directly below 65 space l2, an air supply space 14 below saidpassage, a valve chamber 15 below space 14, and upper and lower airchambers 16 and 17 along the central web 5. Each chamber 17 opensdownward into a discharge nozzle 18 formed upon the bot- '(0V tom 4 anda dispatch tube 19 is connected to said nozzle. At their upper. ends thecasings 1 .are closed by four flat, elongated cover plates 20 which aredisposed edge to edge and extend transversely across all of the casings.Said plates are sup.- 75 ported upon flanges 21 formed upon the upperends of the casings 1, and upon anges 22 formed upon cover sections 2,3.The cover sections 23 are mounted upon the outermost casings 1, atopposite sides of the assembly and detachably held 30 by screws 24.Other screws 25 detachably hold the plates 20 to said supporting 'anges.y

`The casings 1 are all similarly formed and th various webs within thedifferent casings aline edgewise throughout the length of the assembly.95 Therefore at each side of the central web 5 the various spaces andchambers lie in straight rows. Spaces Y12 open, one into another insuccession,

as do the air supply chambers 14. Each casing is formed at one side withwalls 26 which sepa- 9 rate the chambers 15, 16 and 17 of one casingfrom the corresponding chambers of the next adjacent casing and abutsealing flanges 26a formed on said next casing. Abutting walls 26b uponthe successive casings separate the passages 95 13. Along their endswalls 2 and 3 the successive casings are formed with inwardly extendingflanges 27 which abut and are detachably fastened together by screws 28to holdthe casings together. The flanges 27 extend across 100 thecommunicating spaces 12 and across the communicating spaces 14, and thescrews 28 are accessible through said spaces. At their opposite ends therows of communicating spaces 12 are closed by the detachable coversections 105 23. At one end, the rows of spaces 14 are closed by adetachably mounted plate 29 and at the opposite end an air supplymanifold 30 opens into both rows. This manifold is detachably fastenedto the endmost casing 1 and is connected to an |10 istering with thebushing ports 44. This valve a shouldei` 54 bearing against the web 9.

air supply pipe 31. Removal of one of the cover sections 23 and theplate 29 gives access to the screws 28.

Two of the cover plates 20 serve to cover the two rows of chambers 16and are formed with bell mouths 32 defining entrances for the insertionof carriers. Each entrance is located directly over one of said chambersand is normally closed by a pair of trap doors 33. The latter opendownward and are yieldably held closedby springs 34. Beneath eachentrance, within the casing, is a tube section 35, 'disposed in verticalalinement with the entrance. At an intermediate point said tube sectionis formed with an enlarged threaded portion 36 which is screwed into anaperture in the wall 11 separating the chambers 16 and 17 so that thetube section extends into both chambers. Its upper end is flared to forma bell mouth spaced a short distance below the carrier entrance and itslower end terminates near the nozzle 18. Downwardly opening trap doors37 are mounted upon the lower end and are normally held closed bysprings 38. Above the wall 11 the tube section is formed with air ports39 and its bell mouth is notched as at 40 for screwing it into place.The tube section forms a carrier transmission passage as will beexplained hereinafter.

For each terminal there is a valve mechanism to control a flow of airfor propulsion of carriers throughthe tube section 35 and through thedispatch tube 19. Within each chamber 15, which is in effect a lateralbranch of chamber 17, is mounted a cylindrical valve bushing 41. Thelatter is disposed vertically and has its ends fitted in apertures 42formed in the web 10 and the casing bottom 4. Just beneath the web 10the bushing is formed with ports 43 at one level, and at a lower levelit is formed with ports 44. A cylindrical valve 45 is tted to slidewithin the bushing and is formed with ports 46 for regis cup-shaped andopens upward into the valve bushing and the space 14.

The webs 8 and 9 are formed with apertures 47. and 48 respectivelyvertically alining with the apertures 42. A plate 49 is disposed withinthe upper space 12 and is formed with a depressed central portion 50fitting in the aperture 47 and centrally formed with an aperture 51.Said depressed portion of the plate is formed with a downwardlyextending valve cage 52 which terrninates in an annular beveled valveseat 53 which is fitted in the web aperture 5l and provided with Theupper aperture 47 is large enough to permit the insertion of theshoulder 54 through it for mounting the valve seat in place. Screws 55detachably fasten the plate 49 to the web 8 and hold the shoulder 54against the web 9. The plate 49 forms a valve guide and a support forcertain control means within the space 14.

A beveled disk valve 56 is adapted to seat upward against the valve seat53 and is formed with guide lugs tting in the cage 52. Said valve isformed with a tubular stem 57 extending above and below the valve. Abovethe valve said stem slidably iits through the plate aperture 51 andextends upward into the space 12. Below the valve the stem is formedwith a disk valve 58 formed to slidably iit in the upper end of thebushing 41 to close communication between'the air supply space 14 andthe interior of the bushing. Valve 45, Within the bushing, has fixed toit a vertical stem 59 which extends upward through `the tubular stem andis slidably tted in it.V A

compression spring 66 bears against the under side of valve 58 andencircles the stem 57 of valve 45. At its lower end said spring bearsupon several abutment pins 6l which extend upward through apertures inthe bottom of valve 45 and are carried by a bottom plate 62. The lattercloses the lower end or the valve bushing and is detachably held to thebottom of casing 1 by screws. Normally, as shown at the right hand -sideof Fig. 4, the spring 60 holds the valve 56 against its seat 53 andholds the valve 58 elevated above the bushing 41.

Plate 49, within each upper chamber 12, is formed Vwith a pair ofupstanding ears 63 and plvoted between said ears is an angular operatinglever 64. Said lever has an operating handle 65 extending upward througha slot in the adjacent cover plate 20, and a lateral arm 66 whichextends across the upper ends of the valve stems 57 and 59. Foroperatively contacting said stems arm 66 bears a roller 67. kAt its freeend said arm bears a suitably insulated electrical contact disk 68.Beneath said disk the plate 49 bears a pair of spring contact ngers 69suitably insulated. These lingers extend upward and are flared apart attheir upper ends to receive the contact 68 between them when the leveris operated.v Thereby, an electrical circuit, not shown, is closed and,in the usual manner causes the operation of a timer which, in turncontrols the operation of a compressor and causes a ilow of air to theterminal device.

Detachably supported by the upstanding leversupporting ears 63 arebrackets 70 each of which rotatably bears a grooved pulley 71. In thepresent instance, with three terminal units, there are four of thesepulleys for each row of terminals, two of the pulleys being disposedbetween the operating levers and two at the ends of the row. All of thepulleys are at the same level and in each row they are in the sameVertical plane. The brackets 70 at the ends of the rows are providedwith bracket extensions 72 Y which rotatably-bear cross-over pulleys 73.The latter are all disposed at a level below that or" the pulleys 71and'in planes at right angles thereto. Each valve stem 59 also rotatablybears a pulley 74, to provide clearance for which, the tubular stem 57is out away at one side as at 75. These pulleys 74 are disposed in thesame verticaly planes with pulleys 71 and normally are at the same levelas 4the pulleys 70, or substantially so. Trained around all of thepulleys is a ilexible strand in the form of an endless chain 76. Thelatter passes over the pulleys 7l, under the pulleys 74V in a serpentinecourse and under the cross-over pulleys '73, there`- by makingcross-over connections between the two rows of terminals. For laccommodating said cross-over connections the end closure sections 23are outwardly bulged. The chain has only suicient slack to permit thedepression of one ci the pulleys and its connected valve stem 59 at atime. Consequently when a handle is voperated to de-` press one of saidpulleys a previously depressed pulley in either row is automaticallyelevated to normal position by the tension of the chain.

In the operation of the device a carrier is in# serted intoone of theentrances 32 of a terminal whose control means are in the normalposition, shown at the right hand side of Fig. 4. Here the valve 56 isin closed position against the seat 53 and valve 45 is in elevatedclosed position so that communication between the air supply space 14and chambers 16 and 17 is cut off. Also, the valve stems 57 and 59 arein elevated position and their upper ends are coincident. The carrier isinserted by thrusting it through the trap doors 33 and into thetransmission passage dened by the tube section 35, the door springs 34automatically closing the entrance behind the carrier. The control lever64 is then operated to engage the contact 68 with the fingers 69 toclose the timer circuit and start a flow of air through the manifold 30and into the spaces 14. Said operation of lever 64 also depresses valvestems 57 and 59 and their connected Valves 45, 56, and 58. Depression ofvalve 56 opens communication between space 14 and the upper chamber 16.Valve 45 is also in open position but Valve 58 is in a position withinthe bushing 41 and shuts off communication between space 14 and lowerchamber 17. Air which has been admitted to upper chamber 16 enters theupper portion of the tube section 35 and forces the inserted carrier outof the tube section through the trap doors 37, whereupon the latter areclosed by their springs 38. Such operation of one of the terminals isshown in Fig. 6.

The connection for a now of air into chamber 16 exists only while thehandle is held in operated position, ordinarily only a moment. When thehandle is released the spring 60 automatically elevates valve 56 toclosed position and elevates the valve 58 to open position. Such anadjustment is shown in Fig. 4, at the left hand side. Air then iiowsthrough the bushing ports 43 and 44 into the chamber 16, nozzle 18 anddispatch tube 19 for the propulsion of a carrier therealong to itsdestination.

Valve 45 remains in its lower, open position, after the return of theoperating lever to normal position, until another one of said levers isoperated. Then a tension will be exerted upon the chain 76 which willelevate the previously depressed pulley 74, valve stem 59 and valve 45to normal closed position.

The trap doors 33 prevent escape of air while it is flowing into chamber16 and tube section 35 and trap doors 37 prevent escape of air throughthe tube section to the entrance while the air is owing into chamber 17and the dispatch tube. Therefore if a carrier should be inserted intothe entrance 32 while air is still flowing into the dispatch tube, asthe result of a previous operation, escape of said air through theentrance will be prevented by the trap doors 37.

The various parts Within veach casing 1 are readily removable throughthe top of the casing. For removal of the control means for one of theterminals the appropriate cover plate 20 is removed and the plate 49 isreleased from its connections Within the space 12. Then, plate 49,switch 69, contact lever 64, valve cage 52 and the valves 56, 58 and 45are all removable upward as a unit. When it is required to remove one ofthe transmission tubes 35, the adjacent cover plate 20 is removed,giving access to the upper end of said tube and permitting it to beunscrewed and Withdrawn upward.

The device provides for positive and quick pneumatic propulsion of thecarriers from the terminal entrances to the dispatch tubes. It is alsodesigned for convenient installation, maintenance and operation. TheVarious units are interchangeable and are designed for ready assemblyinto a compact form. All of their internal parts are readily accessibleand removable for cleaning, repairing and replacement.

What I claim is:

1. A sending terminal head for a pneumatic dispatch tube line,comprising means dening a carrier entrance; an inwardly opening trapclo'- sure for said entrance; a carrier passage leading -from. theentrance toward the tube line; an exit trap closure for said passagespaced therealong from said entrance closure and opening toward the tubeline; a communication for leading air to said carrier passage forpropelling a carrier through the passage, the entrance trap closurepreventing escape of air through the entrance; a communication forleading air to the tube line at a point beyond said exit trap closure topropel a carrier through the tube line; and valve means to open andclose said communications for the propulsion of a carrier through thesaid passage and through the tube line.

2. A sending terminal head for a pneumatic dispatch tube line,comprising means dening a carrier entrance; an inwardly opening trapclosure for said entrance; a carrier passage leading from the entrancetoward the tube line; an exit trap closure for said passage spacedtherealong from said entrance closure and opening toward the tube line;a. normally closed communication for leading air to said carrier passagefor propelling a carrier through the passage, the entrance trap closurepreventing escape of air through the entrance; a communication forleading air to the tube line at a point beyond said exit trap closure topropel a carrier through the tube line; and valve means to first opensaid rst communication and close said second communication and nextclose the first communication and open the second one for the propulsionof a carrier through the said passage and through the tube line.

3. A sending terminal head for a pneumatic dispatch tube line,comprising means defining a carrier entrance; ,an inwardly opening trapolosure for said entrance; a carrier passage leading from the entrancetoward the tube line; an exit trap closure for said passage spacedtherealong from said entrance closure and opening toward the tube line;a normally closed lcommunication for leading air to the inner side ofthe entrance closure and to said carrier passage for propelling acarrier lthrough the passage, the entrance closure preventing escape ofair through the entrance; a communication for'leading air to the tubeline at a point beyond said exit trap closure to propel a carrierthrough the tube line; valve means manually operable to open said firstcommunication and close said second communication for the propulsion ofa carrier through the passage and the eXit closure; and means toautomatically operate said valve means to close the rst communicationand openy the second one for the propulsion of the carrier through thetube line.

4. A multiple sending terminal head for a pneumatic dispatch tubesystem, comprising a plurality of sending terminal devices eachconnected to a dispatch tube line and comprising a carrier entrance, aninwardly opening trap closure for said entrance, a carrier passageleading from the entrance toward the tube line, an exit trap closure forsaid passage spaced therealong from said entrance closure and openingto-ward the tube line, a communication for leading air to said carrierpassage for propelling a carrier through the passage, the entranceclosure preventing escape of the air through the entrance, acommunication leading air to the tube line at a point beyond said exittrap closure to propel the carrier through the tube line, and valvemeans to open and close said communications for the propulsion of. acarrier through said passage and through the tube line; and means toautomatically restore said valve means ci one sending terminal device tonormal position when the valve means of another device is operated forthe propulsion of a carrier.

5. A sending terminal head for a pneumatic dispatch tube line,comprising means defining a carrier entrance; an inwardly opening trapclosure for said entrance; a carrier passage leading from the entrancetoward the tube line; an exit trap closure for said passage spacedtherealong from said entrance closure and opening toward the tube line;a communication for leading air to said carrier passage for propelling acarrier through the passage, the entrance trap closure preventing escapeof airthrough the entrance; a corrununication for leading air to thetube line at a point beyond said exit trap closure to propel a carrierthrough the tube line; valve means to open and close said communicationsfor the propulsion of a carrier through the said passage and through thetube line; an electric switch to 'control a supply of air to saidcommunications; and manually operable means to operate said switch andoperate said valve means.

6. A sending terminal head for a pneumatic dispatch tube line,comprising means dening a carrier entrance; anl inwardly opening trapclosure for said entrance; a carrierV passage leading from the entrancetoward the tube line; an exit trap closure for said passage spacedtherealong from said entrance closure and opening toward the tube line;a communication for leading air to said carrier passage for propelling acarrier through the passage, the entrance trapY closure preventingescape of air through the entrance; a communication for leading air tothe tube line at a point beyond said exit trap closure to propel acarrier through the tube line; valve means to open and close saidcommunications for the propulsion of a carrier through said passage andthrough the tube line; an electric switch to cause a dow of air to saidcommunications; manually operable means to close said switch and operatesaid valve means to open said first communication and close said secondcommunication tor the propulsion of a carrier through the passage andthrough the exit closure; and means to automatically open the switch andoperate the valve means to close the rst communication and open thesecond one for the propulsion of the carrier through the tube line.

7. A multiple sending terminal head for a pneumatic dispatch tubesystem, comprising a plurality of sending terminal devices eachconnected to a dispatchtube line and comprising a casing provided with acarrier entrance, a passage within the casing for directing a carrierfrom said entrance to the tube line, air conduits. within the casing foradmitting air to said passage and to the tube line for the propulsion ofthe carrier, valve means within the casing to control the flow of airthrough said conduits, means to prevent escape' of airl through theentrance, and manually operable means to operate said valve means; andmeans to automatically restore the valve means of one of said terminaldevices to normal position when the valve means of another of saiddevices is subsequently manually operated.

8. A multiple sending terminal head for a pneumatic dispatch tubesystem, comprising a plurality of sending terminal devices eachconnected to a dispatch tube line and comprising a casing provided witha carrier entrance, a passage within the casing for directing a carrierfrom said entrance to the tube line, an air sup-r ply space within thecasing, conduits leadingy from said space to the carrier passage and tothe tube line for the propulsion of the carrier, and valve means withinthe casing to control the ilow of air-through said conduits; and meansattaching the casings of the several devices side to side, the attachedcasings being formed at their opposed walls to place their air supplyspaces in communication with each other.

9. A sending terminal head for a pneumatic vdispatch tube linecomprising means dening a carrier entrance; a carrier passage leadingfrom the entrance toward the tube line; a communication or leading airto said carrier passage for propelling a carrier through the passage; acommunication for leading air to the tube line to propel the carriertherethrough; valve means to open and close said communications for thepropulsion of a carrier through said passage and through the tube linemeans to prevent air delivered through said rst communication-fromescaping through the entrance; and means to prevent air delivered fromsaid second communication from escaping through the carrier passage tothe entrance.

10. A multiple sending terminal head for a pneumatic dispatchtubesystem, comprising a plurality of sending terminals, each connectedto a dispatch tube; a manually operable device for each terminal tocontrola now of air from a compressed air supply source to the terminalfor propelling a carrier away from the terminal; and means toautomatically restore a previously operated one of said devices tonormal position when another one of said devices is operated.

l1. A multiple sending terminal head for a pneumatic dispatch tubesystem, comprising a plurality of adjacent sending terminals, a manuallyoperable device for each terminal to control a flow of air forpropelling a carrier away froml the terminal; and a flexible strandtrained to engage said air control devices and automatically restore apreviously operated device to normal position when another one isoperated.

Vi2. A multiple sending terminal head for a pneumatic dispatch tubesystem comprising a plurality of rows of adjacent sending terminals; amanually operable device for each terminal to control a flow of air forpropelling a carrier away from the terminal; and a flexible endlessstrand trained to engage all of said air control devices andautomatically restore a previously operated device to normal positionwhen another one is operated.

13. A. multiple sending terminal head for a pneumatic dispatch tubesystem, comprising a plurality of similarly formed, interchangeablesending terminal units attached together, each connected to a dispatchtube and including a manually operable device for each terminal tocontrol a :dow of air from a compressed air supply source to theterminal for propelling acarrier away from the terminal; and means toautomatically restore a previously operated one of said devices tonormal position when another one of said devices is operated.

i4. A sending terminal head for a pneumatic dispatch tube system,comprising a casing open at the top; a cover member for the top of saidcasing provided with a carrier entrance; a dispatch tube line connectionat the lower end of the casing in alinement with said carrier entrance;a carrier Vtransmission tube extending between said entrance anddispatch tube convmunication; and means to automatically close nection,detachably supported in the casing and formed for endwise upwardwithdrawal from the casing when said cover member is removed; andcontrol means detachably supported within the casing for controlling aow of air for the propulsion of'a carrier from the entrance through thetransmission tube and the dispatch tube, the casing and said controlmeans being formed for upward withdrawal of the latter through the topof the casing.

15. A sending terminal head for a pneumatic dispatch tube linecomprising means deiining a carrier entrance; a carrier passage leadingfrom the entrance toward the tube line; a communication for leading airto said carrier passage for propelling a carrier through the passage; acommunication for leading air to the tube line to propel the carriertherethrough; valve means to open and close said communications for thepropulsion of a carrier through said carrier passage and through thetube line including telescoping, relatively shiitable valve stems, apair of valves iixed to one of said stems, one of said valves to controlsaid passage air communication and the other to control said tube linecommunication, and a valve xed to the other stem to cooperate with saidsecond valve for controlling said tube line air communication; means toshift said valves in unison for opening the rst valve, closing thesecond valve and opening the third valve for admission of air to saidcarrier passage; and means to close the rst valve and open the secondvalve independently of the third valve for admission of air to the tubeline.

16. A sending terminal head for a pneumatic dispatch tube linecomprising means dening a carrier entrance; a carrier passage leadingfrom the entrance toward the tube line; a communication for leading airto said carrier passage for propelling a carrier through the passage; acommunication for leading air to the tube line to propel the carriertherethrough; valve means to open and close said communications for thepropulsion of a carrier through said carrier passage and through thetube line including telescoping, relatively shiftable valve stems andcooperating valves upon said stems.

17. A multiple sending terminal head for a pneumatic dispatch tubesystem, comprising a plurality of sending terminals, each connected to adispatch tube; a device for each terminal to control a flow of air froma compressed air supply source to the terminal for propelling a carrieraway from the terminal; and means to automatically restore a previouslyoperated one of said devices to normal position when another one of saiddevices is operated. Y

18. A multiple sending terminal apparatus for a pneumatic dispatch tubesystem, comprising a plurality of carrier sending terminals each havinga dispatch tube connection and a normally closed communication with acompressed air supply source to admit a carrier-propelling flow of airto said tube connection; a manually operable device for each terminal toopen its said coma previously opened air flow communication of oneterminal when the air flow communication of another terminal is opened.

19. A multiple sending terminal apparatus for a pneumatic dispatch tubesystem, comprising a plurality of parallel rows of adjacent carriersending terminals each having a dispatch tube connection and a normallyclosed communication to lead a carrier-propelling flow of air` to saidtube connection; amanually operable device forl each terminal to opensaid communication; andA means to automatically close a previouslyopened air flow communication of any one of they terminals in either rowwhen the air flow communication of any of the other terminals in eitherrow is opened;

20. A multiple sending terminal apparatus for a pneumatic dispatch tubesystem, comprising a plurality of parallel rows of carrier sendingterminals, a manually operable device for each terminal to control aflow of air for propelling a carrier away from the terminal; and aflexible tension strand trained in operative engagement with saidcontrol devices of the rows and Aoperable to automatically restore apreviously operated device in either row to normal position when anotherone of the devices in either row i operated. Y Y

21. A multiple sending terminal apparatus for a pneumatic dispatch tubesystem, comprising a; plurality of carrier sending terminals each havinga dispatch tube connection and a normally closed communication with acompressed' 'air supply source to admit a carrier-propelling'flow of airto said tube connection, a common air supply connection for all of saidcommunications; a manually operable device for each terminal to open itssaid air flow communication; and means.

to automatically close a previously opened air ow communication of oneterminal when the communication of any one of the other terminals issubsequently opened. Y

22. A multiple sending head for a pneumatic dispatch tube system,comprising a plurality of similar, interchangeable, detachably connectedterminal units each having a dispatch tube line connection andcomprising a casing having a carrier entrance, a passage within thecasing for directing a carrier from said entrance to the tube line, anair supply space within the casing, communications leading from saidspace to the carrier passage and to the tube line for the propulsion ofa carrier; and manually operable valve means within the casing tocontrol the ovv of air through said communications, the casings beingdisposed side to side and having their opposed sides open to place theirsaid air supply spaces in successive communication.

23. A sending terminal head for a pneumatic dispatch tube line,comprising a sending terminal having a dispatch tube connection; acommunication to admit a carrier-propelling flow of air to said tubeconnection; a shiftable closure for said communication; a manuallyoperable device to shift said closure to open the communication; and anelectric switch to control a supply of air to said communication andoperable by said manually operable device to close the switch when themanually operable device is operated to shift said closure to openposition.

24. A sending terminal head for a pneumatic dispatch tube line,comprising a sending terminal having a dispatch tube connection;a'communication to admit a carrier-propelling flow of air vto said tubeconnection; a shiftable closure for said communication; a manuallyoperable device to shift said closure to open the communication; anelectric switch to control a supply of air to said communication; anoperative connection between said manually operable device and theswitch to close the switch when the manually operable device is operatedto shift said closure to open position; and means to automatically openthe switch independently of the closure when the said device is manuallyreleased. y

25. A multiple sending terminal apparatus for a pneumatic dispatchtube'system, comprising a plurality of carrier sending'terminals eachhaving a dispatch tube connection and a communication with a compressedair supply means` to admit carrier-propelling air to a dispatch tubeconnectedr to the terminal; a shiftable closure device for each of saidcommunications manually operable to open the communication; and aflexible Ytension strand trained in operative connection with saidclosure devices to automatically Vshifta previously opened one of theclosure devices to closed position when another` one of said devices ismanually operated to open position.

26. A multiple sending terminal apparatus for a pneumaticdispatch tubesystem, comprising a plurality of carrier sending terminals each havinga dispatch tube connection and Aa communication with a compressed airsupply means to admit carrier-propelling air to a dispatch tubeconnected to the terminal; a shiftable closure device for each of saidcommunications manually operable to open the communication; pulleyscarried by said closure devices and shiftable therewith; pulleys mountedin fixed positions; and a flexible tension strand trained by said iiXedand shiftable pulleys to automatically shift a previously` opened one ofthe closure devices to closed position when another one of said devicesis manually operated to open position.

27. A multiple sending terminal apparatus for a pneumatic dispatch tubesystem, comprising a plurality of side -by side rows of carrier sendingterminals, each terminal having a dispatch tube connection and acommunication with a compressed air supply means to admitcarrier-propelling air to ia dispatch tube connected to the terminal, ashiftab-le closure device for each of said communications manuallyoperable to open the communication; and a flexible tension strandtrained in a serpentine course and in operative connection with theclosure devices of both rows to automatically shift a previously openedone oi` said devices to closed position when another one of the devicesis manually shifted to open position.

28. A sending terminal apparatus for a pneumatic dispatch tube system,comprising a plurality of sending terminals each having a dis- Y patchtube connection and also a communication to lead a carrier-propellingiiow of air to said tube connection; a shiftable closure member for eachof said communications; a manually operable device for each ofsaid-closure members to shift it to open the communication; a pluralityof electric switches to control supply of airto said communications andeach operable lby one of said manually operable devices to close theswitch when the said device is operated to shift

